Device for supporting the cervical vertebral column

ABSTRACT

The invention relates to a device for supporting the cervical vertebral column, in particular during flight in an aircraft. Said device consists of a pressurised cushion comprising at least two front cushions ( 5, 6 ), which acts on the region between the head and shoulders of a pilot ( 1 ). The helmet (H) of the pilot is provided with a rest piece ( 4 ) for the chin. Said piece bridges a gap between the front end regions of the front pressurised cushions ( 5, 6 ), covering the upper faces of the front pressurised cushions ( 5, 6 ) and can be displaced in relation to the latter, so that the head ( 1 ) of the pilot can turn freely and his or her chin is prevented from entering the gap.

The present invention relates to a device for supporting the cervicalvertebral column according to the generic term of patent claim 1.

Such a device follows the publication WO/PCT/EP 00/09759. It essentiallycomprises an assembly of pressurized cushions with at least two frontcushions, which face each other in relation to the neck of the user. Onethe one side these two front cushions rest against the shoulder of auser and on the other side they support the undersides of the laterallower jaw area of the user. Moreover, the said device has at least onecushion that is positioned in the rear section of the device that restsagainst the shoulder of the user on one side and supports the occipitalsquama of the user on the other side. These three cushions exert apressure in their effective direction for supporting the head in avertical direction. A control and regulation unit is provided which canselectively raise or lower the pressure in the pressurized cushions.Depending on the tilt of the head and the g-force components measured,this control and regulation unit can build up various countering forcesin the effective direction.

A problem of a device of this kind for supporting the vertebral columnis that the two front pressurized cushions supporting the undersides ofthe lateral lower jaw area make it difficult to turn the head even in azero pressure state when the head is moved toward the front.

In addition, there is the possibility that when the head is tiltedtoward the front under stronger use of force, the chin of the user mayslip through the front areas of both the front pressurized cushions suchthat the force-compensating function is no longer guaranteed and it isadditionally not possible to carry out sideward movements any more.

A further problem of the said invention is the fact that the chin strapof the user's helmet can impair the function of the front cushionsconsiderably. However, a helmet is indispensable.

The task of the present invention is, therefore, to create a device forsupporting the vertebral column that allows for freedom of headmovement.

This task has been realized by a device having the characteristics ofpatent claim 1 for supporting the vertebral column.

The main advantage of the present invention is that the provided chinrest pad attached to the chin strap of the helmet provides specialsupport for the head with the chin on the rest pad on one side andsupport for the rest pad on the front pressurized cushions on the otherside, wherein particularly the existing gap between the front end areasof the front pressurized cushions is bridged over by the rest pad. Sincethe rest pad can easily slide on the front pressurized cushions, it isnow possible to move the head conveniently. This also prevents the headfrom entering into the said gap between the front end areas of the frontpressurized cushions and the resulting injury during strong headmovements toward the front.

Further advantages of the present invention are that in case of g-loads,the forces affecting the head with the helmet of a pilot are partlycompensated on the chin joint and the occipital squama, wherein thefront pressurized cushions at the chin joint take over the compensationin case of a head tilt of up to preferably 30 degrees toward the frontand up to more than 17 degrees toward the back. The back pressurizedcushions at the occipital squama take over the compensation in case of ahead tilt from preferably 22 degrees to preferably more than 40 degreestoward the back. The head is not supported in case of an almost uprightposition from approximately 17 to 22 degrees to the front and to theback and about 5 degrees sideward. The centers of gravity of the headand helmet system almost overlap each other. The relevant g-forces onthe vertebral column are moderate in this position of the head since theg-force component is small compared to the countering forces provided bythe neck musculature. The specified angular degrees refer to the headposition of 0 degrees, in which the center of gravity of the headrespective to the mass of helmet/head lies vertically over the fulcrumon the vertebral column.

During operation without a g-load in case of a head tilt a small amountof pressure in the pressurized cushions maintains the cushions uprightand against the head. Thus almost full freedom of movement is ensured incase of or with little counter bearing pressure.

In case of a g-load up to 6 g the quantum and the vector of the load inrelation to the head position at the moment of this action are recordedby a g-sensor and a control and regulation unit provides a counteringforce to the cushions for the g load to be counter controlled as aresult. Each time, an appropriate control valve actuates thecorresponding pressure pillow, till the default bearing pressure at thehead is achieved. Force sensors on the surface of the pressurizedcushions record the force on the head. This force is compared with a setvalue in the control and regulation unit and eventually thecorresponding control valve is activated to achieve a pressure reductionin the pressurized cushion. In case of an intended movement of the head,the musculature applies an additional small amount of pressure on theforce sensors. The control and regulation unit steer the pressure backand thus enable a movement in the intended direction. In case of anacceleration of over 6 g., the control valves to the pressurizedcushions are opened for maximum pressure supply and then completelyclosed. The head is supported in the case of these loads. The target isnot to achieve a controlled freedom of movement because this isphysically not feasible. The mechanism effectively relieves the cervicalvertebral column of stress by up to approximately 60% and the stress onthe neck musculature by up to almost 100% depending on the position ofthe head and the location of the center of gravity.

Normally in cases of a high g-load, injuries of the cervical vertebralcolumn are expected to occur due to a resulting force that amounts to asmuch as 2.0 times the weight. The device, according to the invention caneffectively avoid such injuries. Likewise the invention can preventstress on the neck musculature that normally leads to exhaustion,blackouts, neurological deficits, coordination disturbances, headaches,partial performance disturbances and a diminished ability toconcentrate.

A further advantage of the present invention is that by using the helmetdisplay, displayed images and information can be seen by the pilotvibration free, because the present device stabilizes the head-helmetsystem.

Dependent claims of this patent further elaborate on the merits of thisinvention.

The invention and its arrangements are explained in better detail in thecontext of the following figures. The figures illustrate:

FIG. 1: a schematic representation for the explanation of the inventionin which the weight center of the head, the pivot point (fulcrum)between the cervical vertebral column and the head and the applicationof force on the neck musculature are shown.

FIG. 2: a perspective representation of a preferred pattern ofconstruction of the device according to the invention, essentiallyconsisting of the resting pad attached to the chin strap of a helmet,the front pressurized cushions with hard surface for the adhesion withthe head part and the shoulder part with the resting case;

FIG. 3: a schematic block diagram of the control and regulation unit forthe explanation of the control of the pressure build-up and pressurereduction in a pressurized cushion; and

FIG. 4: a further training of the invention.

The invention was the result of the following deliberations. Accordingto FIG. 1 the head 1 of a pilot is twisted around the pivot point O withreference to the cervical vertebral column 2. The pivot point O islocated at the upper end of the cervical vertebral column 2. The turningtakes place through the neck's muscular system that acts on the head 1in point F. The tilting movement of the head 1 operates in the oppositedirection. The tilting movement arises from the weight of the head 1 andtries to turn the head 1 around the pivot point O. It is noticeable thatwhile wearing a helmet, especially one fixed with additional equipmentlike for instance sight or after-sight devices, the weight of the head 1and consequently also the tilting moment around the pivot point O aregreatly increased. The corresponding vector is indicated in the FIG. 1with V. In order to avoid the pressure on the head from the front endareas of the front cushions during a large g-load and when the head 1tilts toward the front, such that the function of the cushion is notaffected, according to the invention, a rest pad 4 is attached at thehelmet H, favorably at the belt component K of the helmet H on the sideturned toward the front cushions 5, 6. This resting pad 4 can glide onthe surface of the front cushions 5, 6, in the normal head positionindicated in FIG. 1 without a g-load, during a head tilt in case oflittle pressure in the front cushions 5, 6. Thus an adhesion of thefront cushions 5, 6 with the head 1 is maintained. It is also thenpossible to turn the head conveniently. Almost total freedom of movementcan be ensured with minimal countering pressure.

In case of a high g-load (up to 6 g), the quantum and the vector of theforce in relation to the head position at the moment of the exposure arerecorded by sensors and the control and regulating unit applies acountering force to the cushions that as a result have to be countercontrolled till a preset bearing pressure on the head 1 is attained.During an intended movement of the head 1 an additional small amount ofpressure is applied by the muscular system to the force sensors of therespective front cushions 5,6, so that the control and regulating unitsteers the pressure back and consequently can let a movement in theintended direction. In case of a very big acceleration (over 6 g) thecushions are actuated for a maximum pressure impact, so that the head 1is fully supported during these stresses. A controlled freedom ofmovement is not aimed for, because this is not feasible physically. Bythis mode of operation of the cushions and of the sliding overlying restpad 4, depending on the position of the head and location of the centerof gravity, a reduction of the stress of the cervical vertebral column 2by up to approximately 60% and a reduction of stress on the neckmuscular system by up to almost 100% can be achieved.

According to FIG. 2 the front cushions 5, 6 and the back cushions 7, 8are fastened at the guard zone of an upper opening 12 of a rest case 10.This rest case 10 overlies on the neck and shoulder area of a pilot. Therest case 10 shows in the forefront a port shaped opening 14 that passesdownward which can be widened for putting on the rest case 10, and afterthat is attachable by drawing together the port shaped opening 14 withthe help of at least one locking mechanism 16 running in cross directionwhich might be a Velcro fastener for instance.

The back cushions 7, 8 lie on the upper side of the occipital squama ofthe head 1. The front cushions 5, 6 show integrated stiffening elements18, 20, on which the rest pad 4 can be supported. Each of the cushions5, 6, 7, 8 is fillable with the help of a fluid, especially a gel, aswill be explained in better detail later, so that it can expand in theeffective direction to support the head 1 of the pilot. It has beenindicated that the cushions 5, 6, 7, 8 can be effectively padded usingfoam cushion towards the outside, inside and upwards.

If the rest case 10 overlies on the shoulder area of a pilot and thelocking 16 is locked, the upper sides of the back cushions 7, 8 lie atthe occipital squama of the head 1 of the pilot and the upper sides ofthe front cushions 5, 6 are turned toward the sideward lower jaw areasof the pilot with their stiffening elements 18, 20. The rest pad 4 isfastened to parts of the chin belt 22, 24 of the helmet H that is notrepresented in FIG. 2. It is formed such that in the normal state it canoverlie on the upper sides of the stiffening elements 18, 20 and/or ofthe wrapping of the front cushions 5, 6 that covers these, such that itcan freely glide on the cushion when the head 1 of the pilot turns. Apushing through of the chin area of the head -1 is avoided, because therest pad 4 bridges over the gap between the front end areas of the frontcushions 5, 6 with its front area 4′. The side areas 4″ are formedstretching obliquely outwards from the front area 4′ and overlie uponthe front cushions 5, 6 when the head 1 is upright, so that the slidingmotion of the rest pad 4 cannot be obstructed.

A force sensor 26 is placed on the upper side of each cushion 5, 6, 7,8. It is a piezoresistive pressure sensor that emits an output voltagebetween 0 Volt and 10 Volt as an output signal. This depends on thepressure applied to it and to the respective cushion.

FIG. 3 shows a schematic block diagram of a control and regulating unitfor the production and supply of pressure on each cushion 5, 6, 7, 8,wherein only one cushion 6 has been illustrated in FIG. 3 as an example.A compressor 30 produces the required operating pressure in a reservoir32. The compressor 30 is connected to the cushion 6 via a duct 34 and aregulating valve 36 for pressure-buildup. The regulating valve 36 isactivated via an actuator 38 that is activated by the electronic unit40. In the duct 34 between the regulating valve 36 and the pressurecushion 6 there is a branch circuit 44 with a discharge valve 46, viawhich the built up pressure of cushion 6 is relieved with its activationby the actuator 48, which is also activated by the electronic unit 40.

The electronic unit 40 receives an output signal from a 3D-vectorialg-force sensor via the wire 50. This signal contains information aboutthe respective g-force in three-dimensional space. Depending on thissignal, the electronic unit 40 produces corrective signals for thepressure supply of the cushion 6 via the regulating valve 36 and/or viathe discharge valve 46 for the pressure relief of cushion 6. Thepressure sensors 26 of the cushions 5, 6, 7, 8 supply via the wire 52, apressure signal to the electronic regulating unit 40 indicating therespective pressure in the pressure cushion 6. A range sensor 56 can beprovided in order to supply a range signal to the electronic unit 40 viathe wire 54. The signal indicates the actually occurring expansion ofthe cushion 6 after application of pressure via the regulating unit 36.

The front cushions 5, 6 can show on the inner surface in each caseindentations 28 in the stiffening elements 18, 20, as illustratedschematically in the FIG. 4. The indentations can be covered by thewrapping and can prevent an injurious squeeze of the carotis communisarteries and of the Ingularis veins. Such indentations do not adverselyaffect the support of the front cushions 5, 6 on the lower jaw areas inthe present invention, because they are covered on the upper sides bythe rest pad 4.

The present device can also be used effectively for the compensation ofvibration stresses occurring while flying in helicopters and caused bythe rotor blades of helicopters where the sinusoidal vibrations of thiskind lie in the frequency range of 30 to 100 Hz, and/or in case of sonicfrequencies or frequencies of over 300 Hz transmitted by GFK-aircraftcells with an approximately 0.15 oscillating g-acceleration and in caseof a longer lasting acceleration of an approximate maximum of 4 g. Thevibration stresses originate from either the stimulation of the head byway of the pilot seat and also in case of higher frequencies by thesound pressure of the rotor directly on the helmet via the cabin roofairway. The so-called PIOS (Pilot Induced Oscillations) can also becompensated.

1. Device for supporting the cervical vertebral column, in particularduring a flight in a jet aircraft. The device comprises an assembly ofpressurized cushions between the head (1) and shoulders of a pilot. Thedevice contains at least two front cushions (5, 6) whose front end areasare distanced from each other by a gap and that there is a provision fora rest pad for the chin of the pilot. The device is characterized by thefact that a rest pad (4) is placed at the helmet (H) of the pilot. Therest pad can be laid out to bridge over the gap existing between thefront end areas of the front cushions (5, 6) and can slide with respectto these cushions, so that the head (1) of the pilot can turn freely andhis chin does not enter into the gap.
 2. Device according to claim 1,characterized by the fact that the front cushions (5,6) are attached atthe guard zone of an opening (12) of a rest case (10) lying over theneck and shoulder area of the pilot, such that its upper sides areturned toward the lateral lower jaw areas of the pilot, and that therest pad (4) can slide smoothly on the upper areas.
 3. Device accordingto claim 1, characterized by the fact that the rest pad (4) is attachedto the chin strap (22, 24) of the helmet (H).
 4. Device according toclaim 1 characterized by the fact that the front cushions (5, 6) showintegrated stiffening elements (18, 20) on their upper surfaces, onwhich the rest pad (4) can be supported.
 5. Device according to claim 1,characterized by the fact that the rest pad (4) shows a front area (4′)that bridges over the gap between the front cushions (5, 6). A side areais arranged at each end of the front area (4′) that emerges from thefront area (4′) and stretches obliquely outwards.
 6. Device according toclaim 5 characterized by the fact that the free end areas (4″) of theside areas stretch from the level side area obliquely upwards away fromthe front cushions (5, 6).
 7. Device according to claim 1 characterizedby the fact that the front cushions (5, 6) and the back cushions (7, 8)are arranged at the guard zone of the opening (12) of the rest case(10), wherein the surfaces of the back cushions (7, 8) support theoccipital squama of the head (1) of the pilot.
 8. Device according toclaim 7, characterized by the fact that the stiffening elements (18, 20)of the front cushions (5, 6) each show at least one indentation (28) onthe inner side, by which a pressure on at least one artery is avoidable.9. Device according to claim 1 characterized by the fact that the helmet(H) is connected via chin strap components (22, 24) with the rest pad(4).
 10. Device according to claim 9 characterized by the fact that thechin belt components (22, 24) are fastened to the side areas of the restcase (4).
 11. Device according to claim 2, characterized by the factthat the rest case (10) indicates on the front side a port shapedopening (14) that runs downward away from the front cushions (5, 6) andthat can be opened for putting on the rest case (10) and can be lockedby a locking mechanism (16).
 12. Device according to claim 11,characterized by the fact that the port shaped opening (14) stretchesemerging from the gap